Professor Marcio J. T. da Costa

@workingpaper{Dugato2024,

title = {Curved Nanomagnets: An Experimental Archetype for Skyrmion Stabilization},

author = {Danian A. Dugato and Wesley Jalil and Ramon Cardias and Marcelo Albuquerque and Marcio Costa and Flavio Garcia},

url = {https://www.researchsquare.com/article/rs-4547588/v1},

doi = {10.21203/rs.3.rs-4547588/v1},

year  = {2024},

date = {2024-06-10},

urldate = {2024-06-10},

publisher = {Research Square Platform LLC},

abstract = {In the fields of nanomagnetism and spintronics, the controlled stabilization of mag- netic skyrmions is a topic of great interest for potential applications in data storage and innovative computing systems. This study delves into the intriguing phenomenon of skyrmions on a hexagonal array of curved nanomagnets. Through a combination of atomistic calculation, micromagnetic simulations, and experimental observations, we thoroughly explore the intricate interplay between magnetic parameters, curvature, and interfacial Dzyaloshinskii-Moriya interaction (iDMI) in the formation of these topolog- ically non-trivial magnetic structures. We have observed the spontaneous formation of isolated skyrmions (<150 nm) on a curved nanomagnet matrix of symmetric Pt/Co/Pt multilayer without the necessity of applied fields. Our research sheds light on the pro- found impact of geometric curvature on iDMI, offering invaluable insights for engi- neering and controlling skyrmionic configurations. This work advances nanomagnetism knowledge and sets the stage for designing skyrmion-based technologies.},

howpublished = {Research Square},

keywords = {},

pubstate = {published},

tppubtype = {workingpaper}

}

@workingpaper{cysne2023ultrathin,

title = {Ultrathin films of black phosphorus as suitable platforms for unambiguous observation of the orbital Hall effect},

author = {Tarik P. Cysne and Marcio Costa and Marco Buongiorno Nardelli and R. B. Muniz and Tatiana G. Rappoport},

url = {https://arxiv.org/abs/2307.03866},

doi = {10.48550/arXiv.2307.03866},

year  = {2023},

date = {2023-01-01},

urldate = {2023-01-01},

abstract = {Phosphorene, a monolayer of black phosphorus, is a two-dimensional material that lacks a multivalley structure in the Brillouin zone and has negligible spin-orbit coupling. This makes it a promising candidate for investigating the orbital Hall effect independently of the valley or spin Hall effects. To model phosphorene, we utilized a DFT-derived tight-binding Hamiltonian, which is constructed with the pseudo atomic orbital projection method. For that purpose, we use the PAOFLOW code with a newly implemented internal basis that provides a fairly good description of the phosphorene conduction bands. By employing linear response theory, we show that phosphorene exhibits a sizable orbital Hall effect with strong anisotropy in the orbital Hall conductivity for the out-of-plane orbital angular momentum component. The magnitude and sign of the conductivity depend upon the in-plane direction of the applied electric field. These distinctive features enable the observation of the orbital Hall effect in this material unambiguously. The effects of strain and of a perpendicularly applied electric field on the phosphorene orbital-Hall response are also explored. We show that a supplementary electric field applied perpendicular to the phosphorene layer in its conductive regime gives rise to an induced in-plane orbital magnetization.},

keywords = {},

pubstate = {published},

tppubtype = {workingpaper}

}